Occurrence of a Severe Acute Livestock Poisoning by Borehole Water in Marsabit District, Kenya A Case Study
This article reports on an outbreak of acute livestock poisoning by borehole water that occurred at Kargi in Marsabit District, Kenya in 2000. The borehole had been out of use for 3 years and after its rehabilitation, 7,000 animals died within a day after drinking the water. The most affected were shoats, cattle, camels and dogs with mortalities of up to 90%. Donkeys and humans were only mildly affected with no deaths reported. Clinical signs occurred within 1 hour after drinking the water. Initially, the animals displayed increased frequency of urination, followed by symptoms of respiratory insufficiency, comprising of dyspnea, cyanosis, rapid and weak pulse and general weakness. The signs progressed into methemoglobinuria, sever pain, trebling, convulsions, collapse, coma, and death within hours. Rapid decomposition, brown discoloration of mucous membranes, gastrointestinal tract corrosion and cooked appearance of visceral organs were observed at postmortem. Water samples that were collected from the borehole and neighboring wells contained arsenic (0.2 –66.8 ppm), selenium (1.1 –4.4 ppm) < lead (0.01-0.02 ppm) and nitrates (450-950 ppm) and other contaminants. The deaths were probably due to nitrate poisoning.
The Kenya Veterinarian Vol. 28 2005: pp. 16-19